Both players were knocked out of last Sunday’s loss to the Jacksonville Jaguars, and hadn’t practiced all week, so their absence was expected.

Meanwhile, the club also downgraded cornerback Eric Rowe to out with a groin injury. Rowe had started each of the past two weeks, but was benched after two series last weekend, with veteran Jason McCourty replacing him.

McCourty is a top candidate to start against the Lions, with rookies J.C. Jackson and Keion Crossen also possibly being active for their first regular-season games this season.

The Patriots previously ruled out pass-catching tight end Jacob Hollister (chest), so the club will need to downgrade only three more players for the game.

One intriguing storyline centers around newly acquired wide receiver Josh Gordon, who remains officially questionable because of his hamstring. That gives him 50-50 odds to play.

As for how the Patriots might replace Chung and Flowers, six-year veteran Duron Harmon is a projected starter at safety in place of Chung, while Deatrich Wise Jr. is a top candidate to take the majority of Flowers’ reps. It could also mean that 2017 third-round pick Derek Rivers, a defensive end out of Youngstown State, makes his regular-season debut after missing all of his rookie season with a torn ACL. Chung also was the team’s top punt returner last weekend, a role that is expected to fall to third-year defensive back Cyrus Jones.